Magnus of Füssen was an 8th-century Benedictine abbot and missionary active in southern Germany. Often called the Apostle of the Allgäu, he worked to spread Christianity throughout the region, specifically in the eastern Allgäu. He established a monastic community in Füssen, which grew from a small cell into a significant abbey. His historical life is documented through a legendary biography that contains several chronological inconsistencies, yet he remains a central figure in the religious history of the Allgäu and the Diocese of Augsburg.